Dispersion device and the like



20, 1940- A. BROTHMAN v DISPERSION DEVICE AND THE LIKE Filed Feb. 12,1958 Jim INVENTOR ABRAHAM BEOT/IMl/V m ATTORNEY Patented Aug. 20, 1940 VUNITED STATES arsnr oFFicE DISPERSION DEVICE AND THE LIKE AbrahamBrothman, New York,- N. Y. Application February l2, 1938, Serial No.190,156

8 Claims. (o1. sta -107 finally incorporating the pulverized color intodis! persing media as by means of roller or pebble l mills.

At the present time color dispersion is accomplished by apparatus whichare modified forms of dough kneaders equipped for vacuum evaporation. Ingeneral, the basic principle upon 20 which these devices operate, is thekneading of filter cakes and the dispersing medium until a separation isachieved between the water and the color and medium phase. In thesedevices, due to the mechanical entrapment of some of the 5 water, all ofsaid water is not recovered. Hence,

a subsequent stage of vacuum evaporation of the entrapped water is foundnecessary.

In the herein contemplated process, the forming of the filter-cake isobviated as are also the 30 color dispersion gteps by means of roller orpebble mills. The product obtained is at least equally. as good as thoseobtained in the mentioned older devices and in many instances aresuperior in grin and tinting strength. Further, the men- 35 tioned olderdevices are designed to mix or knead at a slow rate and thus the colordispersionis a relatively slow operation. Also, the first flooded watertends to line the walls of the mixing chamher to cause slippage of themass in preparation 40 and thus reduce the efficiency of v the kneadingaction. These kneaders also inefficiently agitate color pastes of'thinconsistency.

From the above it is .quite apparent that the thorough mixing andagitating necessary for per- 45 feet color dispersion may not beobtained bydevices employing kneading action.

Recognizing these faults, the present invention seeks to provide a noveldevice of simple andinexpensive construction for obtaining better color50 dispersion with less utilization of power and in a shorterperiod oftime; novel means for obtaining rapid and efiicient evaporation ofentrapped Water; providing for the direct use of the tank struck colorto eliminate the necessity of 1 filter- 55 pressing; and generallyshortening the overall time of obtaining paint, printing ink, lacquer,

or other such products, from slurrytank color.

The flushing of color or pigment asaccomplished by the contemplateddevice and method,

entails the following phenomena: 5

1. The preferential wetting of the Waterwetted color or pigment by thedispersing medium.

2 The agglomeration of such medium-wetted particles.

And in consequence- 10 3. The flooding off of the Water (whichoriginally wetted the color) because of the immiscibility of water withthe dispersing medium.

Although the apparatus contemplated is peculiarly adapted to carry outthe process above 15,

set forth, it may also be efficiently used in the manufacture of. taremulsion, lacquer emulsion, ceresin wax emulsion, carnauba wax emulsion,in the blowing of. linseed oil, in the reduction of a silica gel, in thegrinding of tooth paste, in the manufacture of salad dressing, Caarsenate, petroleum wax emulsions, the blending of greases, and aeratinga slurry. The foregoing by no ,means exhausts the possible fields inwhich the invention may be used, but merely indicates the possibilitiesthereof.

With the foregoing in mind, the following specification, based on theaccompanying drawing, describes an apparatus of novel design andincorporating featuresof the invention.

In the drawing: 4

Fig. .1 is'a vertical sectional view of a color dispersion'device asherein contemplated.

Fig. 2 is a similar view of a deflecting unit employed therein.

I Fig. 3 is a top plan view of an impeller unit also used in the device.

Referring now to the drawing in greater detail,

the apparatus preferably comprises a support base 5 upon which aremounted in side by side 40 relation, a power unit such as the motor 6and the flushing unit I. H

In the present instance, the motor is provided with a shaft 8 extendingfrom the bottom of said motor, which is preferably arranged vertical-'1y; and upon said shaft is carrieda pulley 9. In any desirable mannerthe shaft may be provided with suitable support means such as the thrustbearing l0.

The otherend of the motor is preferably provided with a speed reductionunit H from which the shaft 52 is extended. Upon this shaft is carried apulley i3. As at present contemplated,. the pulley 9 is adapted torotate ata relatively high rate of speed, 5,000 to 7,000 B. P. M. or 55thereof, there is provided an impeller unit carried by the shaft I6.This unit comprises a plate portion 2| upon which are arranged aplurality of curved blades or vanes 22 and a pair of arcuate verticallydisposed members 23 concentrically arranged about the center of theimpeller unit. These arcuate members are preferably slotted as at 24 andare arranged so that,

7O{parts within the kettle.

upon rotation of the impeller unit, a cylinder is generated by saidarcuate members. These members are of substantial height, and in thepresent instance are shown as approximately onethird the height of thekettle. I

. It is understood from this arrangement that the impeller unit may berotated at the speed of the motor shaft 8 when the pulleys 9 and I5 areof equal size or at a proportional speed depending upon the relationalsize of said pulleys. In any event, it is desired to obtain a speed ofbetween 5,000 to 7,000 R. P. M. of the impeller unit.

The bottom peripheral edge' of the kettle is preferably rounded as at 25for cooperative action with the impeller for reasons later apparent.

The kettle is formed with a cover 26 which, in the present case, isshown as convexly spherical, said cover being removably secured tosuitable flanges at the open upper end of the kettle. This cover isarranged to revolubly support a deflector unit 2'! as by means of theshaft 28 and a combined bearing and stufling box is provided at 29 forefficient mounting of said deflector unit on said cover.

The deflector unit 21 is provided with deflectors v somewhat short ofthe cylinder generated by the arcuate members 23, and the lower ends ofsaid deflectors are commonly connected by a ring shaped deflector member32 having portions overstanding portions of the impeller vanes.

In a suitable manner, each deflector 30 may carry a scraper member 33having scraping engagement with the inner surface of the kettle wall.

The deflector unit 2! is arranged to be rotated by a belt 34 connectingthe pulley I 3 with a pulley 35 on the deflector shaft 28. The speed ofrotation of this deflector unit is approximately that of the shaft I2 toR. P. M.) and preferably in an opposite direction to the rotation of theimpeller unit.

The kettle is provided with a connection 36 to.

vacuum and condenser apparatus and in the present instance theconnection is made to the cover 26 so as to be located above the movingA vacuum gauge 31 also may be provided as shown.

It is preferred to heat the wall of the kettle and for this purpose saidkettle is formed with a jacket 38 through which steam may be circulatedfrom a steam inlet 39 to an outlet 40. Also, the

water resulting from the flushing operation may approximating thisspeed, and the pulley I3, at a,

be drawn off through a cock 4| connected to the bottom of the kettle.

In operation, a quantity of dispersing medium is placed vinthe bottom ofthe kettle. For paint, raw linseed oil may be used; for lithographicprinting ink, boiled linseed oil; and for lacquers, plasticizers, suchas castor oil. The water-wetted color or pigment is added, the coverapplied to the kettle, and rotation of the impeller and deflector unitsstarted.

The impeller, rotated at a high rate of speed, is designed to give themixture of water-wetted color and dispersing oil the following type ofagitation:

The high speed of the impeller causes centrifugal ejection of allmaterials coming in contact therewith. The ring 32 prevents directupward movement of the materials except beyond its outer peripheraledge. Hence, this flattening action of the ring causes said material tobe directed towards the walls of the kettle and to climb said walls to aheight which is limited by the flow and density of the materialinvolved. This upward movement of the material is aided by the roundedbottom edge 25 of the kettle which acts to minimize the reactive forceswhich might cause other than smooth flow of the materials under theurgency of the impeller blades. In this manner a vortex is formed in theflow of the materials which move upward at the sides of the kettle anddownward at the center thereof.

The cylinder which is generated by the rotational speed of the arcuatemembers 23, serves various purposes. During the stage when there isuniformity in the materials being mixed, said generated cylinder seeksto maintain the central portion of the impeller free of materials. Thisaidsthe formation of a vortex having downwardly moving materials withinsaid cylinder to cause more eflicient expulsion of such materials whichfall into said cylinder. During the stage when water is flooded off fromthe mass, the space enclosed by said generated cylinder serves as apaste agglomerant collection chamber and simultaneously acts as a focalpoint of the vortex produced in the water circuit, insuring continuedcontact between the color and oil phase and said water circuit.

' The arcuate members also act to chop the paste 'agglcmerants deflectedinto their path by the deflectors. The slots in said arcuate membersalso serve to do this. Incases of very thin paste, where the generatedcylinder does not act as a collection chamber, the chopping and shearingactions of these members insure the absence of livers from the pasteproduced. As herein understood, a liver comprises a plurality of colorparticles having a common envelope of oil. Since this condition isundesirable the above action is important.

The above-mentioned vortex also serves to incorporate air into themixture. This is desirable not only to ease agitation but also becausethis air serves, in vehicles of a higher density than water, to floatthe color and vehicle phase substantially in the manner mineral ores arefloated.

The deflector ring, in addition to preventing the direct upward movementof the materials, also serves to prevent overloading of the impeller byintercepting and retarding the paste agglomerants which seek to falldirectly thereon and in addition shear the materials between itself andthe impeller.

Briefly. then, the flushing occurs as follows:- The above-mentionedmixture of dispersing medium (oil) and water-wetted color is subjected(ill i101 the aforesaid action until water (color free) is noticedcirculating through thevortex. The mixture is then rested in the case ofthinpastes, and a separation of the water from the non-water phases iseffected. The valve 4! is used for this purpose. After the water isremoved, a suitable thinner for the paste such as mineral spirits,toluol, xylol, or butyl acetate, etc. is added for the purpose ofincreasing the flow properties of the paste and therefore the efficiencyof the heat transfer from the steam jacket. The thinning solvent thusadded may in some cases contribute directly to the acceleration of theevaporation by acting as a carrier for the water.

After the thinner has been added and the steam circulated in the jacket,a vacuum condition is introduced into the flusher through the connection36, and the water and thinner evaporated under these conditions arecondensed in a suitable condensation apparatus. This condition iscontinued until a satisfactory freedom from water or dryrress isachieved in the mass. Of course, the choice of a thinning solventdepends upon the finished pain-t, enamel, ink, or lacquer. Wherevernecessary, thinning more solvent may be added from time to time.

After the water has been evaporated, those materials which are necessaryto complete the product, may be added and the mixing continued until asatisfactory uniformity of texture is achieved. In this stage of theprocess, the agglomerant collecting properties of the generated cylinderholding said agglomerants in the focal point of the vortex, makes thisfinal stage of the process a quick one.

From the above, it may be seen that the active phase of flush-ing (theflooding off of water due to the exchange of dispersing media by thecolor or pigment) as produced by this process, is based on the followingprinciples:

1. The intimate intermixing of materials (color, water, and dispersingvehicle) by means of a high speed mixing mechanism of the turbine type.

2. The charging of each phase due to violent mixing, rapid translationof the mixed materials, and shearing action; and the accomplishment ofthe flooding off of water due to the opposite charging (electrostaticcharges) of color particles and dispersing vehicle particles.

3. The mechanical production of a vortex to accomplish the inclusion ofair into the mixture and simultaneously entrapping the paste phase inthe vortex to insure continuous operating contact between water andnon-water phases.

4. The entrappinzg of air into the non-water phase to makepossible theflotation of the paste phase and also tomake easier the subsequentvacuum evaporation stage.

5. The maintenance of maximum shearing action to insure the mostintimate intermixture of the various phases present in the mass, andalso, where filter-press cake instead of slurry tank color is used, toinsure that the color is in its ultimate particle size.

also beused for mixing water paints such as casein paints.

From the foregoing disclosure, it is readily apparent, that a noveldevice has been provided for the flushing of colors; and that the methodemployed for the process above-described is also new, simple, and moreeconomical than prior processes. However, this disclosure should beconsidered as exemplary only, since many variations may be incorporatedby those skilled in the art. For this reason, the prior pertinent artrather than the instant disclosure, should form the basis ofinterpretation of the spirit and scope of the invention as claimed.

What I claim as new and desire to obtain by Letters Patent, is:

1. A dispersion device or the like comprising a kettle, means forrapidly agitating a mass of materials in said kettle to cause upwardflow of said materials along the walls of said kettle, means carried bysaid agitating means for receiving agglomerants formed in said mass ofmaterials, said means also acting to shear materialscontacting them, andmeans for retarding the flow of agglomerants outside said receivingmeans towards said agitating means.

2. A color dispersion device comprising a kettle adapted to receive amixture of water-wetted color and a dispersion medium, means for rapidlyagitating said mixture to cause an upward flow thereof along the wallsof said kettle, means for deflecting said flow towards the center of thekettle comprising flow deflector members, means for receivingagglomerants formed in the downwardly flowing central mass of themixture and for guiding said agglomerants towards said agitating means,and means for retarding the flow of agglomerants outside said receivingmeans towards said agitating means.

3. In a dispersion device or the like, an agitating unit comprising arotating impeller for causing flow of a mass of materials in saiddevice, means on said unit for receiving and seeking to retain theagglomerants formed in said mass by the mentioned agitating means, saidreceiving means comprising vertically disposed arcuately shaped membersadapted to generate a cylinder during rotation of said impeller and toshear materials contacting them.

4. In a dispersion device or the like, an agitating unit comprising arotating impeller for causing flow of a mass of materials in saiddevice, and means on said unit for receiving and seeking to retain theagglomerants formed in said mass by mentioned agitating means, saidreceiving means comprising vertically disposed arcuately shaped membersadapted to generate a cylinder during rotation of said impeller, saidarcuate members being slotted to cause shearing and chopping of thematerials contacting them.

5. A device of the character described comprising a kettle, a rotatingimpeller mounted in said kettle for agitating a mass of materialstherein, a member positioned above said impeller to induce an upwardflow of said materials along the vertical walls of said kettle, meansfor deflecting said fiow in a direction transverse to the mentionedflow. and means carried by the impeller for receiving a cylindricalportion of the downward flowing mass of materials, the mentioned memberalso acting to retard the remainder of said downward flow towards saidimpeller,

6. In a device of the character described, an impeller, a memberdisposed above the impeller ing the remainder of the flow from abovetowards the center of said impeller, and means for rotating the impellerand the mentioned member at different rates of speed.

8. In a'device of the character described, an impeller, means on theimpeller for directing the central portion of a 'fiow from above to thecenter of said impeller, means for rotating said impeller, a memberdisposed above and in spaced relation to said impeller, the peripheralportion of said member extending beyond the outer periphery of saidimpeller to guide the flow from said impeller in an outward direction,the said member also retarding the remaining portion of the flow fromabove towards the impeller, fiow deflecting means connected with saidmember, and means for rotating said member and said flow deflectingmeans.

ABRAHAM BRO-TI-IMAN.

